N, S, and Cl tri-doped carbon boost the switching of radical to non-radical pathway in Fenton-like reactions: Synergism of N species and defects

Shizhe Xu; Pengfei Wang; Xueyue Mi; Yueping Bao; He Zhang; Fan Mo; Qixing Zhou; Sihui Zhan

doi:10.1016/j.jhazmat.2023.133321

N, S, and Cl tri-doped carbon boost the switching of radical to non-radical pathway in Fenton-like reactions: Synergism of N species and defects

J Hazard Mater. 2024 Mar 15:466:133321. doi: 10.1016/j.jhazmat.2023.133321. Epub 2023 Dec 20.

Authors

Shizhe Xu¹, Pengfei Wang¹, Xueyue Mi¹, Yueping Bao¹, He Zhang¹, Fan Mo¹, Qixing Zhou², Sihui Zhan³

Affiliations

¹ MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Carbon Neutrality Interdisciplinary Science Center, College of Environmental Science and Engineering Nankai University, Tianjin 300350, China.
² MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Carbon Neutrality Interdisciplinary Science Center, College of Environmental Science and Engineering Nankai University, Tianjin 300350, China. Electronic address: zhouqx@nankai.edu.cn.
³ MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Carbon Neutrality Interdisciplinary Science Center, College of Environmental Science and Engineering Nankai University, Tianjin 300350, China. Electronic address: sihuizhan@nankai.edu.cn.

PMID: 38301438
DOI: 10.1016/j.jhazmat.2023.133321

Abstract

Heteroatom doping represents a promising strategy for enhancing the generation of singlet oxygen (¹O₂) during the activation of peroxymonosulfate (PMS) using carbon-based catalysts; however, it remains a formidable challenge. In this study, we systematically controlled the structure of metal-free carbon-based materials by introducing different heteroatoms to investigate their efficacy in degrading organic pollutants in water via PMS activation. The results of reactive oxygen species detection showed that the dominant free radical in the four samples was different: CN (•SO₄^- and •OH), CNS (•O₂^-), CNCl (¹O₂), and CNClS (¹O₂). This led to the transformation of active species from free radicals to non-free radicals. The tri-doped carbons with nitrogen, sulfur, and chlorine (CNClS) exhibited exceptional performance in PMS activation and achieved a remarkable degradation efficiency of 95% within just 6 min for tetracycline. Moreover, a strong linear correlation was observed between the ratio of pyridine-N/graphite-N and I_D/I_G with the yield of ¹O₂, indicating that N species and defects play a crucial role in CNClS as they facilitate the transition from radical to non-radical pathways during PMS activation. These findings highlight the possibility that adjustable tri-heteroatom doping will expand the Fenton-like reaction for the treatment of actual wastewater.

Keywords: Heteroatom; Peroxymonosulfate; Singlet oxygen; Water purification.